This or a similar warning is emitted by a plugin that processes plain text files but has not been configured to
use a specific file encoding. So eliminating the warning is simply a matter of finding out which plugin emits it
and how to configure the file encoding for it. This is as easy as adding the following property to
your POM (or one of its parent POMs):

If you understand the layout of the Maven repository, you can copy the jar directly into where it
is meant to go. Maven will find this file next time it is run.

If you are not confident about the layout of the Maven repository, then you can
adapt the following command to load in your jar file, all on one line.

mvn install:install-file
-Dfile=<path-to-file>
-DgroupId=<group-id>
-DartifactId=<artifact-id>
-Dversion=<version>
-Dpackaging=<packaging>
-DgeneratePom=true
Where: <path-to-file> the path to the file to load
<group-id> the group that the file should be registered under
<artifact-id> the artifact name for the file
<version> the version of the file
<packaging> the packaging of the file e.g. jar

This should load in the file into the Maven repository, renaming it as needed.

So, if you have subscribed to users@maven.apache.org then you would
send a message to users-unsubscribe@maven.apache.org in order to
get off the list.
People tend to have problems when they subscribe with one address and
attempt to unsubscribe with another. So make sure that you are using the
same address when unsubscribing that you used to subscribe before
asking for help.

If you find you still cannot get off a list then
send a message to [mailing-list]-help@maven.apache.org. These
instructions are also appended to every message sent out on a maven mailing
list ...

Add the parameter -Dmaven.test.skip=true or -DskipTests=true in the command line,
depending on whether you want to skip test compilation and execution or only execution. See the example
Skipping Tests
in the Surefire Plugin's documentation for more details.

Tests are run by the surefire plugin. The surefire plugin can be configured to run certain test classes and
you may have unintentionally done so by specifying a value to ${test}.
Check your settings.xml and pom.xml for a property named "test" which would like this: